solve euler055.
solve euler059.
solve euler092.
solve euler082.
solve euler085.
use DP to solve euler076 as change-counting.
solve euler063.
add a clearer (but still slow) solution for 31.
move change-counting into a reusable module.
some partial infrastructure for euler098.
solve euler098, albeit a bit ugly.

At least it's fast, though.
clean up euler098 a little bit.
add a naive (i.e. too slow) solution for euler062.
add some partial code for euler060.
add some partial code for euler100.
Fix A-5 Straight bug.
Add missing import
Solve euler 57
Merge branch 'master' of github.com:vin/challenge